Blog

When to Plant Cabbage in Gilpin County, CO

Gilpin County, Colorado Zone 5b May

May in Gilpin County, Colorado — your action list

A quick May briefing for Gilpin County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 14
Avg. first frost September 26
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Move cabbage from tray to bed

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

Coming up in June — start thinking about
  • Starting indoors: cabbage

Instant PDF download. No spam, unsubscribe any time.

Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

Gilpin County, Colorado is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 6,444 feet, Gilpin County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Cabbage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cabbage successfully. Mulch heavily to conserve soil moisture.

Gilpin County, CO (Zone 5b) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Gilpin County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jul 5 – Aug 30
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jul 16 – Sep 10
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Aug 12 – Oct 7

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Gilpin County

How your county's soil matches Cabbage's growing requirements.

Soil pH

Your soil pH (6.8–8.0) overlaps with Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Gilpin County is excellent for Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Cabbage.

How to Plant Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cabbage

2
successive plantings in your 135-day season

Sow every 6.9 weeks. Last sowing by Jun 18 to harvest before frost.

For a dedicated fall crop, sow by Jul 18.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 463 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cabbage

Cabbage needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Cabbage Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 3.9" 1.8" 2.1" 🚿 Regular watering
Jun 3.9" 1.4" 2.5" 🚿 Regular watering
Jul 3.9" 1.7" 2.2" 🚿 Regular watering
Aug 3.9" 2.1" 1.8" 💧 Light watering
Sep 3.9" 1.3" 2.6" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Gilpin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cabbage Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cabbage needs ~860 GDD — county provides 1,451 GDD Excellent fit

Cabbage Planting Timeline — Gilpin County, CO

Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow April 30 Apr 30 – May 21
Harvest July 16 Jul 16 – Sep 10
Fall Sowing July 18 Jul 18 – Aug 1

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Fall Sowing Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 1-2 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

135 days in Gilpin County

Growing Tips for Cabbage in Gilpin County

Direct sow Cabbage outdoors after May 14 in Gilpin County when soil has warmed and frost danger has passed.

Common pests for Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Gilpin County receives only 19" of rain annually. Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cabbage in Gilpin County, CO?

Gilpin County is in Zone 5b with an average last frost of May 14. Plan your Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gilpin County, CO?

Gilpin County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 26.

🌱

Your Gilpin County Garden Planner — Free

A 24-page printable planner built for Gilpin County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Gilpin County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.